Re: [LKP] [sched/numa] a43455a1d57: +94.1% proc-vmstat.numa_hint_faults_local

From: Peter Zijlstra
Date: Thu Jul 31 2014 - 11:57:39 EST


On Thu, Jul 31, 2014 at 12:42:41PM +0200, Peter Zijlstra wrote:
> On Tue, Jul 29, 2014 at 02:39:40AM -0400, Rik van Riel wrote:
> > On Tue, 29 Jul 2014 13:24:05 +0800
> > Aaron Lu <aaron.lu@xxxxxxxxx> wrote:
> >
> > > FYI, we noticed the below changes on
> > >
> > > git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
> > > commit a43455a1d572daf7b730fe12eb747d1e17411365 ("sched/numa: Ensure task_numa_migrate() checks the preferred node")
> > >
> > > ebe06187bf2aec1 a43455a1d572daf7b730fe12e
> > > --------------- -------------------------
> > > 94500 ~ 3% +115.6% 203711 ~ 6% ivb42/hackbench/50%-threads-pipe
> > > 67745 ~ 4% +64.1% 111174 ~ 5% lkp-snb01/hackbench/50%-threads-socket
> > > 162245 ~ 3% +94.1% 314885 ~ 6% TOTAL proc-vmstat.numa_hint_faults_local
> >
> > Hi Aaron,
> >
> > Jirka Hladky has reported a regression with that changeset as
> > well, and I have already spent some time debugging the issue.
>
> Let me see if I can still find my SPECjbb2005 copy to see what that
> does.

Jirka, what kind of setup were you seeing SPECjbb regressions?

I'm not seeing any on 2 sockets with a single SPECjbb instance, I'll go
check one instance per socket now.


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